Electrical power control system

ABSTRACT

An electrical power control system for use with a recreational vehicle or similar load to selectively control power thereto from either a utility power source or a generator power source comprising a power control stage coupled to the utility power source and the generator power source by a power supply stage to operate the electrical power control system and a utility/generator switch arrangement to selectively direct the power from either the utility power source or the generator power source to the recreational vehicle wherein the power control stage monitors polarity, phase and voltage levels, and controls the utility/generator switch arrangement to selectively feed power from either the utility power source or the generator power source to the recreational vehicle under a predetermined plurality of operating parameters or conditions and fault conditions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

An electrical power control system for use with a recreational vehicleto selectively control power thereto from a either utility power sourceor a generator power source.

2. Description of the Prior Art

Various types of metering equipment are available to measure, controland display the operating conditions and parameters of electricalsources. Unfortunately such equipment does not generally provide unifiedoperation or important electrical functions to operate RVs reliably andeasily. For example, the AC coil noise is very annoying, especially ifthe products are mounted behind the bedroom cabinets or under the bed.Contact jitter caused by marginal voltage often results in damagingcontactor failure. Contactor failure can cause a potentially hazardousopen neutral condition. Mechanical interlocks are commonly used toprevent malfunctioning contactors from causing multiple contactors frombeing engaged simultaneously. Add-on surge protectors are commonly usedbut only connect to the source wiring or a single point of protection.

Existing equipment includes measurement and controlling circuitrydirectly connected to the source wiring without isolation. This mayallow faulty wiring hazards to be connected directly to system controlsand monitors.

Load management is generally operated with voltage or load currents butdoes not account for source phases. Most voltage measurement andmonitoring equipment uses rectified average voltage measurements anddoes not work on modified sine or square wave sources such as solidstate generators, inverters and uninterruptible power supplies withdesired accuracy.

Examples of the prior art are found in U.S. Pat. No. 4,499,385 and U.S.Pat. No. 4,617,472.

SUMMARY OF THE INVENTION

The present invention relates to an electrical power control system foruse with recreational vehicles and similar loads to providecomprehensive electrical power control management to selectively controlpower from either a utility power source or generator power source andto protect the electrical system and appliances of the load from damage.

The electrical power control system comprises a power control stage toprovide multiple methods of power control and system protection. Thepower control stage also provides faulty wiring protection. For example,in a 240 volt application such as with a recreational vehicle (RV) ormarine application, wiring is critical. Initially, when plugging into ordisconnecting from the 240 volt source, there is an instant of time whenthe electrical plug makes connection to line 1 and line 2 while theneutral is open. This can result in damaging voltage applied to thecircuits and equipment that can cause failures or even fire. RV andmarine manufacturers warn to “turn off” breakers before connecting anddisconnecting external power sources. Although important, the damage tothis wiring is often forgotten or ignored. The power control stage, whenpowered up, will analyze the incoming power for a predetermined periodof time such as three seconds, insuring all wiring conditions are goodand that voltage is within preset operational limits and only then feedsor supplies power to the RV. That is when the incoming power isdetermined to be acceptable, the power control stage will then apply thepower to the load. While the system is operating, the wiring isconstantly analyzed. If a wire becomes loose the power control stagewill disconnect the power. When the power control stage detects faultywiring, a utility or generator contactor opens, a wire fault indicatorilluminates, and an LED displays the fault source electrical powercontrol system also includes low and high voltage protection preventingdamage to appliances from poor service voltage, faulty service wiring,too long service connections, faulty generators, too long extensioncords, too small extension cords and similar circuit deficiencies.

The power control stage controls the supply of power from the utilitypower source or the generator power source when within a predeterminedvoltage range such as from about 102 volts to about 135 volts. The powercontrol stage performs RMS calculations over time to determine theactual operating voltage. The average of the RMS voltage is displayed ona digital LED. If the voltage is out of the preset operational limit orrange, but within a second predetermined range or limit such as fromabout 85 volts to about 150 volts, the power control stage will allow atemporary by-pass of a voltage fault disconnection. The power controlstage will flash the display to indicate operating in a by-pass mode.When power is removed, the by-pass state will automatically turn off.Voltage conditions below about 85 or above about 150 volts will notoperate in by-pass mode and the power control stage will disconnect thepower to the load. The power control stage employs RMS voltagetechnology to accurately measure all power source parameters.

Surge protection or transient suppression on the input power sourcelines and contactor output power lines, protects devices and appliancesthroughout the RV or load by absorbing surges up to about 5,000 jouleswith a maximum withstanding surge current of about 50,000 amps.

The electrical power control system is operable in three selectablemodes. A delay mode provides a delay of power to be supplied to the RVat initial power on or after power is restored after a fault conditionhas interrupted the supply of power to the load. A sequence mode employsload management to sequence on heavy loads, such as air conditioners, onand off. Sequencing provides a delay on connection as well as reversesequencing if the voltage falls below a predetermined value. Sequencingpermits hands free management of the devices and appliances in the RV touse all available power without the operator manually turning on and offthe devices and appliances. The sequence mode also allows the unit to bepowered on in 3 seconds while providing automatic delays for the airconditioners or similar heavy loads. An unrestricted mode provides nodelay or load management.

An optional remote digital console can be used to display and operatethe electrical power control system from the cab or other remotelocation. The advantage of using the remote digital console is that adisplay allows the operator to conveniently observe the operating RMSvoltage or any fault condition as well as the ability to enter theby-pass mode of operation from the interior of the coach or otherlocation.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts that will beexemplified in the construction hereinafter set forth, and the scope ofthe invention will be indicated in the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to an electrical power control systemcapable of monitoring wiring conditions, voltage polarity, phase andlevels to selectively supply and transfer utility power or generatorpower to an operating load such as a recreational vehicle, motor coachor similar load. The electrical power control system employs low andhigh voltage and wiring fault disconnects and surge protection ortransient suppression on the input source lines as well as the loadlines to protect the operating load. The effective RMS voltage isdisplayed on a primary control and display and on an optional remoteconsole. LED status indicators allow easy diagnosis of fault conditionsthat may prevent proper coach operation. A by-pass switch can be used toallow the load to operate when the voltage is out of predeterminednormal operating range, but within a predetermined minimum and maximumvoltage range. A second by-pass switch can be located on the optionalremote console.

The electrical power control system tests for fault conditions andvoltage as shown in Table 1.

TABLE 1 Display Explanation GEN Generator power on delay (20 seconds)LO_(—) Low voltage (less than 102 Vac) HI_(—) High voltage (greater than135 Vac) Gnd Open Ground Neu Open Neutral Pol Reverse Polarity E_H ExtraHigh Voltage (greater than 150 Vac) “flashing” By-pass mode FLT Line 1or Line 2 open wiring fault — Processing delay for new readings CFLInternal communication fault between microprocessors dIA Internaldiagnostic error

The electrical power control system is selectively operable in one ofthree operating modes: delay, sequence and unrestricted. In the delaymode, the electrical power control system will delay the closing orcoupling circuits or contactors for a predetermined time such as 2.5minutes to compensate for air conditioners in the load without internaltime delays. The sequence mode closes or completes the appropriatecontactors or circuits and controls the air conditioners in the loadindependently providing sequenced delays at start up as well as sheddingof A/Cs for low voltage power management. The unrestricted modeoperation is without sequencing and delay and is used on loads that haveincorporated other means of load control.

In the delay mode, the electrical power control system initiallydisplays a power on status for a predetermined period of time such asthree seconds; and if a wiring or voltage fault is detected, theappropriate code is displayed. If there are no fault conditions, theelectrical power control system delays power to appropriate contactorsor switch arrangement for a predetermined period of time such as 2.5minutes and a delay enunciator is illuminated. A by-pass switch may bepressed to override or by-pass the delay if the electrical power controlsystem is operating within predetermined ranges. The electrical powercontrol system will power on the generator contactor or switcharrangement if the generator is on and operating within acceptablelimits or the utility contactor or switch arrangement if the coach isconnected to shore power and the supplied voltage and wiring are withinacceptable operating ranges or limits. The generator has priority ifboth the generator power source and the utility power source are presentand within acceptable operating parameters, limits or ranges. If thepower source changes and the generator comes on-line, the “GEN” will bedisplayed for a predetermined time such as 20 seconds then transfer thesource of power to the generator. If the shore (utility) power source isconnected while the generator is operational, the electrical powercontrol system will continue to operate with power from the generator.Wire diagnostics are only enabled on the active source of power. An LEDdisplays the average voltage of the two power lines if both are suppliedor single line if only one is available. If a wiring or voltage faultcondition occurs, the contactor switch arrangement will power off andthe specific cause for the fault will be displayed. The voltage levelfault conditions are qualified for a predetermined period of time suchas eight seconds to prevent temporary line fluctuations from tripping afault condition. If the voltage is out of normal range and the operatorwants to power-up the coach, the operator can shut-off all inductiveloads including air conditioners and the like and press the by-passswitch to engage the appropriate contactor or switch arrangement. Adisplay will flash the voltage reading while in the by-pass mode. Thevoltage must be within a predetermined operating range or limit such asgreater than about 85 Vac and less than about 150 Vac and without wiringfault conditions such as open ground or open neutral for by-passoperation. If the operator presses the by-pass switch and the displayflickers once but the electrical power control system does not enter theby-pass mode of operation, the condition cannot be by-passed.

In the sequence mode, the electrical power control system initiallydisplays a power on status for a predetermined period of time such asthree seconds; and if there are no fault conditions and generator poweris applied, the electrical power control system will display GEN for apredetermined period of time such as twenty seconds then the generatorcontactor or switch arrangement will close to supply power to the load.If there are no fault conditions and shore (utility) power is applied,the electrical power control system will power on or close the utilitycontactor or switch arrangement. The generator has priority if bothpower sources are active. Optional A/C relays will be sequenced on aftera first predetermined period of time such as a 2.5 minute delay on loadA/C #1 and after a second predetermined period of time such as 8additional seconds for load A/C #2 if the supply voltage is sufficientand repeated for additional control load outputs. The A/Cs will besequenced off if operating voltage falls below a predetermined voltagelevel such as about 102 Vac for more than a predetermined period of timesuch as eight seconds. After the load A/Cs have been shed, theelectrical power control system requires the source voltage to begreater than a predetermined voltage level such as about 108 Vac tosequence the A/C loads on. If the power source changes and the generatorcomes on-line, the GEN will be displayed for a predetermined period oftime such as twenty seconds then switch over to generator. If the shore(utility) power is connected while the generator is operational then theelectrical power control system will continue to operate from thegenerator as long as the generator is on and within operating limits.Wire diagnostics are only enabled or read on the active source. An LEDdisplays the average voltage of the two power lines if both are suppliedor a single line if only one is available. If a wiring or voltage faultcondition occurs, the contactors or switch arrangement will be poweredoff and the specific cause for the fault is displayed. The voltage levelfaults are qualified for a predetermined period of time such as eightseconds to prevent temporary line fluctuations from tripping a faultcondition. If the voltage is out of the predetermined operating rangeand the operator wants to operate the coach, after the electrical powercontrol system has shed the A/Cs, the operator can press the by-passswitch and the appropriate contactor will engage. A display will flashthe voltage reading while in the by-pass mode. The voltage must bewithin a predetermined operating range or limit such as greater thanabout 85 Vac and less than about 150 Vac and without wiring faultconditions such as open ground or open neutral for by-pass operations.If the operator presses the by-pass switch and the display flickers oncebut the electrical power control system does not enter the by-pass modeof operation, the condition cannot be by-passed.

Additional features are available that allow one or two loads tooperate. Specifically, if the incoming power source has only one phase,less than all the load appliances will be energized simultaneously, andif the incoming power source has two phases all the load appliances canbe energized. The electrical power control system allows load switchingthat may be alternated at intervals to roll the loads.

In the unrestricted mode, the electrical power control system initiallydisplays a “power on” status for a predetermined period of time such asthree seconds. If there are no fault conditions and generator power isapplied, the electrical power control system will display GEN for apredetermined period of time such as twenty seconds then close thegenerator contactor or switch arrangement. If there are not faultconditions and shore power is applied, the electrical power controlsystem will power on the utility contactor. The generator has priorityif both power sources are active. The selected power source is shown onthe load enunciators and a control signal supplied on load managementoutputs. If the power source is utility shore power then the A/C #1output is activated. If the power source is generator power then the A/C#2 output is activated.

The control processor's program may be modified or upgraded byconnecting to the programming/expansion ports. The ports serve multiplefunctions, such as a development emulation port, programming input, ornetwork interface. In addition, there is a detected automotive typenetwork interface that can be programmed with various type of protocolsincluding RV-C and J1939 industry standards. The operation of theelectrical power control system with the multiple ports allowsprogramming, emulation and networking to be used simultaneously.

As shown in FIG. 1, the electrical power control system 10 of thepresent invention is coupled between a recreational vehicle 11 or otherload and a utility power source 14 and a generator power source 16 toselectively control the supply or electrical power thereto. Theelectrical power control system 10 comprises a power supply stage 12coupled to the utility power source 14 through lines L1A, NA and L2A andto the generator power source 16 through lines L1B, NB and L2B and apower control stage 18 coupled to the power supply stage 12.

The power supply stage 12 comprises an isolated low voltage directcurrent electrical power control system power supply 19 and analternating current load power supply including a utility contactor orswitching power relay 20 and a generator contactor or switching powerrelay 24 coupled to the coach 11 through lines L1C, NC, and L2C, and tothe power control stage 18 through an interlock selector or switch 28. Autility detector 22 and a generator detector 26 are coupled between theutility power source 14 and the power control stage 18 and between thegenerator power source 16 and the power control stage 18 respectively.In addition, a contactor or switch diagnostic device or circuit 30 iscoupled between the processor power supply 19, utility power source 14,generator power source 16, utility switching power relay 20, generatorswitching power relay 24, load 11 and the power control stage 18.

Surge suppressors or protectors 32, 34, and 36 are coupled between thepower supply stage 12 and the coach 11, the utility power source 14, thepower supply stage 12 and earth ground 38 and the generator power source16, the power supply stage 12 and earth ground 38 respectively. Surgesuppressors 32, 34 and 36 (not shown) may comprise fuses and detectorsor the like to interface with power control stage 18. The power controlstage 18 may further include a system status console with display and aremote indicator display indicated as 40 and 42 respectively.

As shown in FIG. 2, the isolated low voltage direct current electricalpower control system power supply 19 comprises an input stage 50 and anoutput stage 52 coupled through a filtered high voltage switchingconverter stage 54 and an isolation stage 56. The input stage 50comprises dual utility full wave rectifiers 58 and dual generator fullwave rectifiers 60 coupled by lines L1A, NA and L2A, and lines L1B, NBand L2B to the utility power source 14 and the generator power source 16respectively to selectively supply power therefrom. The dual full waverectifiers 58 and 60 allow voltage to feed to the input stage 50 fromany line to neutral or line to line of either the utility power source14 or the generator power source 16. The filtered high voltage switchingconverter stage 54 comprises an input line filter 62 that reduceselectro magnetic interference or EMI of the electrical power controlsystem 10 and a switching controller 64 to drive the isolation stage 56that comprises an isolation transformer 66 to step down the voltage andan isolated feed-back optoisolator 68 to regulate the output stage 52.The output stage 52 rectifies and filters the isolated low voltage powerat about +12 Vdc and a regulated digital supply power at about +5 Vdc.

FIG. 3 shows the details of the power control stage 18 with power inputsand outputs. The power control stage 18 comprises a control processorstage 74 coupled to the system status console 40 and a load managementstage 80, by-pass control or switch 84, operating mode control orselector 86, emulation header 88 and multi-use serial peripheralinterface or SPI header 90. The control processor stage 74 comprisescircuitry 96 including a microcontroller 98 with firmware to control theoperation of the electrical power control system 10, a detectorsinterface 92 and a remote console interface 94. The control processorstage 74 performs the centralized controls using the system inputs andcomparing these inputs to predetermined bi-level thresholds to preventcycling along with an internal time base and timers and output tocontrol the switching power relays 20 and 24 and system statusindicators 40 and 42. The load management stage 80 comprises a driverinterface integrated circuit 104 coupled to connectors and a pluralityof LEDs 106 to indicate the status of each output to allowmicrocontroller 98 to selectively enable any combination of theplurality of loads AC1, AC2 and AC3 within the coach 11. The operatingmode control or selector 86 permits an operator or user to select thetest/delay/sequence/unrestricted operation mode of the electrical powercontrol system 10. By placing jumpers the operation may be configuredfor test diagnostics, delay, sequence or unrestricted mode programming.The emulation header 88 provides a port to the microcontroller 98 todownload programs and also to perform emulation control. The multi-useSPI header 90 provides a multi-use port to program the microcontroller98, to provide an expansion interface, to interface to other processorbased devices and to network to other devices. The system status console40 includes enunciators 100 to indicate the status of the electricalpower control system 10 to display various operation conditions such aswire faults, voltage faults, delay status and by-pass activation. Thesystem status console 40 includes a segmented digital display 102 toshow the source RMS voltage as well as operational conditions such asdelay, generator delay and wiring faults.

FIG. 4 discloses the details of the utility detector 22 or the generatordetector 26 coupled between the utility power source 14 and the powercontrol stage 18 and between the generator power source 16 and the powercontrol stage 18 respectively. The detectors 22 and 26 comprise a powersupply stage 120 and a high voltage input signal conditioning stage 122each coupled to an input utility power source and a microcontroller 124,and an isolated data output stage 126 coupled to the microcontroller124.

In the preferred embodiment source voltage, frequency, phase and wirediagnostics are monitored. Of course, the source current can also bemonitored. The power supply stage 120 rectifies lines L1A and L2A withrespect to NA voltage or L1B and L2B with respect to NB, dropping,filtering and regulating to supply constant voltage of about +3V to themicrocontroller 124. The high voltage input signal-conditioning stage122 rectifies lines L1A, L2A and earth ground 38 with respect to NA orL1B and L2B and earth ground 38 with respect to NB and further scalesand filters the input voltages. These three level shifted and filteredsignals are fed to the microcontroller 124 for analysis. Themicrocontroller 124 receives the conditioned input signals and performsconversions and calculations on these input signals. The voltages areconverted to numeric values using an analog to digital converter in themicrocontroller 124 processing by a Root-Mean-Square (RMS) algorithmsimultaneously with phase and frequency measurement and instantaneousvalue comparison. The RMS value and input power source frequency arecomputed over a number of input power source periods and stores theresults for a sampling period. The phase measurement is performed thatcompares lines L1A and L2A to NA or L1B and L2B to NB and stored for thesampling period in internal memory. The instantaneous data converted bythe analog to digital converter is numerically filtered and compared topredetermined thresholds for fast decision control. The isolated dataoutput stage 126 is coupled to the microprocessor 124 to feed two outputsignals and one input signal between the microcontroller 124 and thepower control stage 18 through the detectors interface 92. The operationof detectors 22 and 26 using the microcontroller 124 provides packets ofdata to be fed to the control processor stage 74 each sampling periodalong with a high speed signal FA that interrupts the control processorstage 74 upon the requirement to react for fast decision control. Thepackets of data periodically sent to the control processor stage 74contain numeric values of line L1A or L1B RMS voltage, line L2A or L2BRMS voltage, earth ground RMS voltage, source frequency and parametricdata of phase and status flags of predetermined threshold comparisons.These packets of data are sent when the control processor stage 74initiates the transmission with a series of synchronous clock pulses.The high-speed signal FA can interrupt the control processor stage 74 atany time and is used to signal the control processor stage 74 toimmediately open the switching power relays 20 or 24 due to a hazardouscondition such as open neutral, open ground, or extremely low or highvoltage.

As shown in FIG. 5, the utility switching power relay 20 is coupled tothe utility power source 14 by surge protector 34, the generatorswitching power relay 24 is coupled to the generator power source 16 bysurge protector 36 and ground is connected to the coach 11 by the surgeprotector 32 and the selector switch 28. Specifically, the utilityswitching power relay 20 comprises a contactor with protected DC coil140 and contacts 142 with inputs coupled to surge suppressor metal oxidevaristors (MOV) 34 and utility power source 14 lines L1A, L2A and NA.Similarly, the generator switching power relay 24 comprises a contactorwith protected DC coil 146 and contacts 148 with inputs coupled to surgesuppressor MOVs 36 and the generator power source 16 of lines L1B, L2Band NB. DC coils 140 and 146 are used to prevent audible hum and toeliminate chatter. The outputs contactor contacts of 142 and 148 arecoupled together and to the coach. The fail safe interlock selector orswitch 28 comprises a transistor switch 136 coupled through a selectorrelay 138 to provide fault tolerant operation preventing both switchingpower relays 20 and 24 from being activated simultaneously. The surgesuppressor 32 comprises MOVs coupled to the coach connection acrosslines L1C and L2C to NC to provide protection for high voltage transientproduced within the coach 11. The surge suppressors 34 and 36 arecoupled to the utility 14 and generator 16 connections across the linesL1A and L2A to NA and the lines L1B and L2B to NB respectively toprovide high voltage transient protection for the respective powersources. The surge suppressor 132 including the utility surge protector34 and the generator surge protector 36 (FIG. 1) comprises circuit boardmounted MOVs that protects the system from surges in lines L1A and L2Aand NA (utility surge protector 34) and lines L1B and L2B and NB(generator surge protector 36) to earth ground 133.

As shown in FIG. 6, the isolated contactor diagnostics 30 comprises aneutral diagnostic stage 160 and a line diagnostic stage 162 bothcoupled between the switching power relays 20 and 24 and the powercontrol stage 18. The neutral diagnostic stage 160 comprises anoptoisolator that is coupled between the neutrals of utility NA andgenerator NB and coach NC and the power control stage 18 diagnostic lineCND. The CND signal is active low when voltage is present on the coachneutral NC with respect to either the source neutrals NA or NB. Thepresence of an active low signal on CND signals power control stage 18and a neutral contact indicates a switching power relay malfunction. Thepower control stage 18 immediately deactivates the switching powerrelays 20 or 24 and displays a fault code on the system status console40 and the remote indicator 42. The line diagnostics stage 162 comprisesan optoisolator coupled between the neutrals of utility NA and generatorNB and coach lines L1C and L2C and the power control stage 18 diagnosticline CLD. The CLD signal is active low when voltage is present on thecoach lines L1C or L2C with respect to either the source neutrals NA orNB. The presence of an active low signal on line CLD signals the powercontrol stage 18 that voltage is present on the coach 11. The powercontrol stage 18 checks the CLD signal before either switching powerrelay 20 or 24 is activated to analyze for malfunctioning, welded orstuck contacts and checks after either switching power relay 20 or 24 isactivated to analyze for malfunctioning open contacts and if eitherfault condition occurs, the power control stage 18 deactivates or opensthe activated or operating switching power relay 20 or 24 and displays afault code on the system status console 40 and the remote indicator 42.In other words, anytime a faulty contactor 20 or 24 is diagnosed, thecontrol processor stage 74 of power control stage 18 prevents anyfurther activation of the activated or operating switching power relay20 and 24. Further, the CLD signal is used by control stage 18 fortiming the power source transfer of utility 14 to generator 16 orgenerator 16 to utility 14 dynamically based on the power relay dropouttime. This provides as fast as possible transfer switching to minimizethe effects of lost power during the transfer such as digital dockslosing time or AC re-setting.

FIG. 7 shows a front view for the electrical power control system 10 andthe hookup detail. The housing 172 further contains circuitry with theinputs for power sources 14 and 16 as well as the outputs to the coach11, the load management relays 108 and 110 and the chassis groundconnection 38 and the remote console 42 connected with modular cable170. The remote console 42 contains segmented displays as well asindicator lamps for system monitoring and a by-pass input switch tocontrol the operation of the electrical control system 10.

It will thus been seen that objects set forth above, among those madeapparent from the proceeding description are efficiently obtained sincecertain changes may be made in the above construction without departingfrom the scope of the invention, it is intended that all mattercontained in the above description are shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, in all statements of the scope of the invention which, is amatter of language might be said to fall there between.

Now that the invention has been described:

1. An electrical power control system for use with a recreationalvehicle or similar load to selectively control power thereto from eithera utility power source or a generator power source comprising a powercontrol stage coupled to the utility power source and the generatorpower source by a power supply stage wherein said power supply stageincludes a low-voltage direct current power supply to operate theelectrical power control system and a utility/generator switcharrangement to selectively direct the power from either the utilitypower source or the generator power source to the recreational vehicleand wherein said power control stage includes a control processorsection to monitor polarity, phase and voltage levels, and a loadmanagement section to control the operation of the electrical powercontrol system to control the utility/generator switch arrangement toselectively feed power from either the utility power source or thegenerator power source to the recreational vehicle under a predeterminedplurality of operating parameters or conditions and fault conditions.